You are really downplaying some of this team's problems.
First off, Nady will help, but he is not a difference maker. Second, there is reason to be concerned that some of these guys will not right themselves. A-Rod has been awful. This is probably the worst he has ever been. Now there are a number of reasons why this might be the case, and one of them is that he is just slumping. However, if it is one of those other reasons, then we might have a big problem. Guys like Nick Swisher, Melky Cabrera, Robinson Cano, and Hideki Matsui (4 of the 9 starters) are too inconsistent right now to be sure that they'll be a big help as this season progresses.
As for the starting rotation, Joba Chamberlain and C.M. Wang are huge concerns. AJ Burnett and Andy Pettitte are very inconsistent. And it remains to be seen whether or not CC's injury is at all serious.
Kilo is right about a couple things. Things are never as good as they seem when you are winning, and things are never as bad as they seem when you are losing. However, he is also right that you use the "we'll be fine" mantra way too much. You have absolutely no substantial reason to be as optimistic as you are. Things may turn out fine, but they also may not. Right now, there is just as many reasons to think that things will turn out poorly as there are reasons to think things will turn out well.